Fanconi-Bickel syndrome

What it is

From: Orphanet

A rare glycogen storage disease due to a deficiency in solute carrier family 2, facilitated glucose transporter member 2 and characterized by hepatorenal glycogen accumulation leading to severe renal tubular dysfunction and impaired glucose and galactose metabolism.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal hepatic glycogen storage · Very frequent (99-80%)

Change in normal glycogen storage content.

Failure to thrive · Very frequent (99-80%)

Failure to thrive (FTT) refers to a child whose physical growth is substantially below the norm.

Hyperphosphaturia · Very frequent (99-80%)

An increased excretion of phosphates in the urine.

Hypophosphatemia · Very frequent (99-80%)

The concentration of phosphate ion in the blood circulation is below the lower limit of normal.

Impaired glucose tolerance · Very frequent (99-80%)

An abnormal resistance to glucose, i.e., a reduction in the ability to maintain glucose levels in the blood stream within normal limits following oral or intravenous administration of glucose.

Increased hepatic glycogen content · Very frequent (99-80%)

An increase in the amount of glycogen stored in hepatocytes compared to normal.

Renal tubular acidosis · Very frequent (99-80%)

Acidosis owing to malfunction of the kidney tubules with accumulation of metabolic acids and hyperchloremia, potentially leading to complications including hypokalemia, hypercalcinuria, nephrolithiasis and nephrocalcinosis.

Galactose intolerance · Very frequent (99-80%)

Abdominal distention · Frequent (79-30%)

Distention of the abdomen.

Glycosuria · Frequent (79-30%)

An increased concentration of glucose in the urine.

Growth delay · Frequent (79-30%)

A deficiency or slowing down of growth pre- and postnatally.

Hepatomegaly · Frequent (79-30%)

Abnormally increased size of the liver.

Metabolic acidosis · Frequent (79-30%)

Metabolic acidosis (MA) is characterized by a fall in blood pH due to a reduction of serum bicarbonate concentration. This can occur as a result of either the accumulation of acids (high anion gap MA) or the loss of bicarbonate from the gastrointestinal tract or the kidney (hyperchloremic MA). By definition, MA is not due to a respirary cause.

Postprandial hyperglycemia · Frequent (79-30%)

An increased concentration of glucose in the blood following a meal.

Other findings in the same source

From: Orphanet

Additional reported features include Rickets (Frequent (79-30%)); Fasting hypoglycemia (Frequent (79-30%)); Hypercalciuria (Frequent (79-30%)); Bone fracture (Occasional (29-5%)); Bowing of the long bones (Occasional (29-5%)); Diabetes mellitus (Occasional (29-5%)); Elevated circulating alanine aminotransferase concentration (Occasional (29-5%)); Elevated circulating alkaline phosphatase concentration (Occasional (29-5%)); Elevated circulating aspartate aminotransferase concentration (Occasional (29-5%)); Generalized aminoaciduria (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 200.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only. Prevalence at birth: 1-9 / 1 000 000; Israel; Value and class. Prevalence at birth: 1-9 / 1 000 000; Specific population; Value and class.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing Fanconi-Bickel syndrome is Metabolic Medicine, with a metabolic specialist / clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with metabolic specialist / clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Is a biochemical or molecular result needed to clarify the diagnosis?
• Does this condition require an individual plan for illness or reduced food intake?
• Should nutrition advice come from a specialist metabolic dietitian?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Fanconi-Bickel syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.